Monodisperse Zn ferrite nanospheres and its Ba substitution nanosheets: Synthesis and magnetic properties

Monodisperse Zn ferrite nanospheres and its Ba substitution nanosheets were successfully prepared by a facile solvothermal method. The size, morphology, and structure of the as-prepared products were investigated in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Magnetic studies revealed that Zn ferrite nanospheres are ferrimagnetic with a saturation magnetization (M-S) of 49.6 emu/g and M-S increased from 49.6 emu/g to 84.2 emu/g when Ba2+ was substituted into Zn ferrite to form BaZn ferrite nanosheets. To explain the variations of morphology and magnetic properties, the strong preferential occupancy of cations in chemically equivalent A and B sites and the metastable cation distribution in nanoparticles are invoked. (C) 2008 Elsevier Ltd. All rights reserved.